In vitro antioxidant and free-radical scavenging activities of polar leaf extracts of Vernonia amygdalina.

BACKGROUND: Plants are able to deliver a huge number of differing bioactive compounds which may supplement the requirements of the human body by acting as natural antioxidants. Antioxidants are mindful for the defense component of the life form against the pathologies related to the assault of free radicals. The main purpose of this study was to investigate the qualitative phytochemical composition of Vernonia amygdalina leaf extract and its antioxidant activity. METHOD: The powdered plant sample was successively extracted with aqueous, methanol and ethanol solvents using Soxhlet apparatus. The antioxidant activities of the crude leaf extract were determined using 1, 1- diphenyl-2-picryl hydrazyl (DPPH) radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical, phosphomolybdate (PM) and hydrogen peroxide (H2O2) scavenging assay. All the examinations were drained triplicates and average values of each test were taken. RESULTS: Phytochemical investigation of the plant revealed that the three solvent extracts contained numerous bioactive compounds namely alkaloids, tannins, saponins, phenols, terpenoids, steroids, glycosides and sugars. The result showed that, the leaf extracts of V. amygdalina obtained from methanol extract exhibit the maximum antioxidant activity compared ethanol and aqueous extracts. The IC50 values of DPPH assay for the H2O, MeOH and EtOH extracts were 111.4, 94.92 and 94.83 µg/ml; of ABTS assay were 334.3, 179.8 and 256.9 µg/ml; of H2O2 assay were 141.6, 156 and 180.6 µg/ml, respectively. The maximum radical scavenging activity was obtained in DPPH assay while the lowest scavenging activity was obtained in ABTS assay method. The data obtained in the in vitro models clearly suggest that methanol extract has higher antioxidant activity due to a higher presence of phenolic constituents in the extract. CONCLUSION: This study revealed that V. amygdalina leaf has a noteworthy antioxidant and free radical scavenging activity mitigating the traditional use of the plant for different aliments.

Antioxidant, Antibacterial, and Anti-diabetic Activity of Green Synthesized Copper Nanoparticles of Cocculus hirsutus (Menispermaceae).

The emergence of new technologies has led to the discovery of the biological properties of nanoparticles through green approach. In the present investigation, we report the potential antibacterial, antioxidant, and anti-diabetic properties of copper nanoparticle (CuNPs) synthesized by reducing 3 mM copper acetate solution with aqueous leaf extract of Cocculus hirsutus. A colour change from deep brown to dark greenish brown indicated the formation of copper nanoparticles. The so-formed CuNPs were characterized by employing UV spectroscopy, FTIR, SEM, and EDX analyses which described sheet-like structure morphology having typical size of 63.46 nm. Later, the synthesized CuNPs efficiency was evaluated against bacterial pathogens, and was found highly toxic to B. subtilis and S. aureus strains. The synthesized CuNPs were examined through H2O2 and PMA assays which demonstrated the highest free radical scavenging activity. Besides, the resulted CuNPs revealed the higher anti-diabetic efficacy in both the [Formula: see text]-amylase and [Formula: see text] -glucosidase inhibition assays (64.5% ± 0.11 and 68.5% ± 0.11, respectively). Finally, our findings report that C. hirsutus can be exploited as a source for green synthesis of CuNPs, having potent in vitro antioxidant, antibacterial, and anti-diabetic properties.

Evaluation of nutritional value and antioxidant activity of Leea macrophylla Roxb. ex Hornem. root and leaf.

Background: Hanshia dabar or hathkan is one of the folklore plant of Odisha, the botanical source of which is Leea macrophylla Roxb. ex Hornem., family Vitaceae. Its root and leaves are eaten as vegetables, and used for Rasayana purpose (tonic and alterative properties). Aim: The aim is to assess the nutritive value and antioxidant potential of the root and leaves of L. macrophylla with compound leaf. Materials and methods: Nutritional parameters such as energy value, carbohydrate, protein, true protein, fat, mineral contents, and Vitamin A, Vitamin C of the root and leaves of the plant were evaluated with standard procedures. The in vitro antioxidant properties of the root and leaf of L. macrophylla were screened through 1,1diphenyl2picrylhydrazyl (DPPH) assay, the ferric reducing antioxidant power (FRAP) assay, and phosphomolybdenum assay. Results: Root is having higher energy value (391.87 Kcal/100 g) as compared to leaf (353.62 Kcal/100 g). L. macrophylla root and leaf showed the presence of carbohydrates (30.65% and 21.72%), protein (8.78% and 9.37%), true protein (6.85% and 7.23%), fat (0.77% and 1.89%), iron (723.80 ppm and 285.07 ppm), zinc (26.51 ppm and 13.75 ppm), manganese (44.88 ppm and 35.00 ppm), phosphorous (0.07 ppm and 0.03 ppm), calcium (7806.90 ppm and 3862.80 ppm), Vitamin A (3.63 mg/g and 2.47 mg/g), and Vitamin C (8.49 mg/g and 6.7 mg/g), respectively. Percentage scavenging of DPPH radical was found to rise with an increase in concentration. IC50 values of root and leaf, by DPPH assay, were 66.46 and 110.68 µg/ml, respectively. In the FRAP assay, the antioxidant activity of the methanolic extract of leaf (507.06 µmol/l) was found to be more than root (455.93 µmol/l). The total antioxidant capacity of root and leaf were 20.15 and 17.90 mg, equivalent to ascorbic acid on a dry weight basis, respectively. Conclusion: Root and leaf of L. macrophylla has the highest energy value, contains carbohydrate, protein, fat, iron, zinc, manganese, phosphorous, calcium, Vitamin A, and Vitamin C, and possesses antioxidant capacity.

Development and validation of the spectrophotometric method of butaphosphan determination in veterinary preparations.

A simple and sensitive method has been developed for the determination of butaphosphan in single- and multi-component veterinary preparations. The method is based on the combustion of organic matter prior to the formation of phosphate and the subsequent formation of the phosphoric­molybdenum complex in the presence of molybdate and ascorbic acid as a reducing agent in the sulfate acid medium. The intensity of light absorption of the colored analytical form of "molybdenum blue" is measured at a wavelength of 830 nm in the range of 0.3-9.0 µg/ml of butaphosphan, where Beer's law is obeyed, has been measured. The reaction conditions and other experimental parameters influencing the reaction transition and the stability of the colored complex have been thoroughly investigated and optimized for the quantitative determination of butaphosphan. Validation of the developed method according to the requirements has been carried out State Pharmacopoeia of Ukraine garmonised with European Pharmacopoeia and its suitability for the analysis of the selected veterinary preparations for the quantitative content of butaphosfan has been confirmed. The results of the determination of butaphosphan in six veterinary preparations of domestic and imported products have been obtained with the help of the developed method. The received results are in agreement with the results obtained by the method of potentiometric titration.

New Chemical Constituents from the Bark of Dendropanax morbifera Leveille and their Evaluation of Antioxidant Activities.

Four new constituents, as cis-6-oxogeran-4-enyl-10-oxy-O-ß-arabinopyranosyl-4'-O-ß-arabinopyranosyl-2''-octadec-9''',12''',15'''-trienoate (1), geran-3(10)-enyl-1-oxy-O-ß-arabinopyranosyl-4'-O-ß-arabinopyranosyl-2''-octadec-9''',12''',15'''-trienoate (2), geranilan-8-oxy-O-α-d-xylopyranosyl-2'-n-octadec-9'',12'',15''-trienoate (3), 1-cyclohex-2', 5'-dienyl 1-cyclohexylethanol-O-ß-d-xylopyranoside (4), along with six known constituents, guaiacol-O-ß-d-arabinopyaranoside (5), n-tetradecanyl oleate (6), oleyl-O-ß-d-xyloside (7), n-octadec-9,12-dienoyl-O-ß-d-arabinopyranoside (8), linolenyl-O-ß-d-arabinofuranoside (9) andglyceryl-1,3-dipalmito-2-olein (10), were isolated and identified from the Dendropanax morbifera bark. The new structures were established by one-and two-dimensional NMR (and in combination with IR, FAB-MSand HR-ESI-FTMS. The comparative evaluation of antioxidant potential by phosphomolybdenum, DPPH, FRAP and the NO assay of four different compounds (1-4), we have found that the compounds 1 and 2 have power as a natural antioxidant, whereas the compound 3 and 4 exhibited mild activity in comparison to compounds 1 and 2.

Biologically active novel N, N, O donor tridentate water soluble hydrazide based O-carboxymethyl chitosan Schiff base Cu (II) metal complexes: Synthesis and characterisation.

Water soluble hydrazide based O-carboxymethyl chitosan Schiff base ligands have been prepared from chitosan and a mixture of benzoic acidhydrazide with ß-diketone by carboxymethylation using mono chloroaceticacid (MCA) through in-situ reaction. The degree of deacetylation of chitosan was determined by elemental analysis and potentiometric titration. Schiff base ligands and the functional groups were characterised by FT-IR, 1H, and 13C NMR spectroscopic techniques. The crystallinity of ligands and complexes was evaluated by X-ray powder diffraction (XRD) studies. Thermal stability of all the synthesized compounds was investigated by thermo gravimetric analysis and differential thermal analysis (TGA-DTA) which revealed the presence of metal oxide (CuO) residue to elevate the temperature to >500 °C. Filed emission scanning electron microscopic (FESEM) analysis revealed that Cu (II) complexes were more amorphous in nature than chitosan and Schiff base ligands. Vibrating sample magnetometer (VSM) studies reported that the d9 configuration of the metal complex was paramagnetic in nature and the geometry of the complex was square pyramidal. The antimicrobial activity of the synthesized hydrazide Cu (II) complexes was characterised by agar plate method, anti-inflammatory study was characterised by egg albumin denaturation technique and total antioxidant activity was characterised by phosphomolybdenum method.

Flow injection programmed to function in batch mode is used to determine molar absorptivity and to investigate the phosphomolybdenum blue method.

The ultimate goal of flow-based analytical techniques is to automate serial assays of a target analyte. However, when developing any reagent-based assay, the underlying chemistry has to be investigated and understood a step, which is almost always the most challenging component of the optimization effort. The difficulty lies in that almost all reagent-based assays were initially developed and optimized in a batch mode, with the aim to perform assays manually, within a time frame of up to 15 min, while flow injection techniques are designed to monitor concentration gradients at times prior to reaching chemical equilibria and while performing up to two assays per minute. This work resolves this discrepancy by using programming Flow Injection (pFI) that operates in a batch mode within a time frame of 1 min or less, with the aim of optimizing an assay under the same conditions and using the same instrument in which the assay will be performed. This novel concept is verified by determining a molar absorptivity of Fe(II) ferrozine complex and by comparing it with literature data. Next, the pFI-batch technique was used to investigate and optimize the phosphate assay, based on formation of phosphomolybdenum blue, with the aim of maximizing sensitivity and improving the limit of detection of this widely used method.

Effects and improvements of different reagents preservation methods on the determination of phosphate in seawater by phosphomolybdenum blue spectrophotometric method.

This work attempted to prolong the validity of the molybdate mixed solution and ascorbic acid solution used in the phosphomolybdenum blue spectrophotometric method by improving their preservation according to the influence factors. The results showed that the molybdate mixed solution can be directly preserved in darkness with validity over half a year. The ascorbic acid solution is influenced by light, temperature, pH, metal ions, oxygen, and bacteria. The validity of ascorbic acid is shortened as the temperature rises. Through keeping in darkness, adding complexing agents, adjusting pH, removing oxygen and sterilization, the validity of ascorbic acid solution was prolonged to over 2.7 times under 4 °C and over 5 times under 25 °C. At the same time, the hybrid solution of ascorbic acid solution and molybdate mixed solution should be preserved separately, otherwise the using effect is poor.

Determination of traces of phosphate in sea water automated by programmable flow injection: Surfactant enhancement of the phosphomolybdenum blue response.

An assay protocol, based on programmable Flow Injection (pFI), is optimized by tailoring flowrates appropriately to the individual steps of an assay, thus allowing sample and reagent metering, mixing, incubation, monitoring and washout to be carried out more efficiently and in different time frames. This novel approach to flow based methods is applied here to optimize the determination of orthophosphate at nanomolar levels. Programmable Flow Injection was also used to facilitate an investigation of the properties of the phosphomolybdenum blue (PMoB) formed during this assay, by using the stop flow technique - an approach that revealed for the first time the influence of surfactants on the kinetics of formation of PMoB and its spectral characteristics. It was discovered that the two most frequently used surfactants (SDS and Brij) have profound and different influences on the spectra and formation of PMoB and this finding was used to enhance the sensitivity of the phosphate assay at nanomolar levels. The method was applied to the assay of trace levels of phosphate in sea water.

Optimization of ultrasound-assisted extraction of antioxidant compounds from Tunisian Zizyphus lotus fruits using response surface methodology.

The optimization of antioxidant extraction conditions from a ripe edible fruits of Zizyphus lotus (L.) with an ultrasound-assisted system was achieved by response surface methodology. The central composite rotatable design was employed for optimization of extraction parameters in terms of total phenolic content and antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and phosphomolybdenum assay. The optimum operating conditions for extraction were as follows: ethanol concentration, 50%; extraction time, 25 min; extraction temperature, 63°C and ratio of solvent to solid, 67 mL/g. Under these conditions, the obtained extract exhibited a high content of phenolic compounds (40.782 mg gallic acid equivalents/g dry matter) with significant antioxidant properties (the total antioxidant activity was 75.981 mg gallic acid equivalents/g dry matter and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity was 0.289 mg/mL).

Study of Polyphenol Content and Antioxidant Capacity of Myrianthus Arboreus (Cecropiaceae) Root Bark Extracts.

In order to evaluate the therapeutic potential of polyphenolic extracts from root bark of M. arboreus, we have determined the content of various polyphenols in aqueous and ethanol (EtOH) extract as well as two sub-fractions of the latter: ethyl acetate (EAc) and hexane (Hex). The total phenols, flavonoids, hydroxycinnamic acids and proanthocyanidins have been determined for all studied extracts/fractions by spectrophotometric methods. Both TP content (331.5 ± 2.5 mg GAE/g) and HCA content (201 ± 1.5 mg CAE/g) were determined to be the highest in EAc fraction of EtOH extract. All studied extracts were however determined to have a low content in flavonoids. The determination of antioxidant capacities of the studied extracts has also been performed by the following in vitro antioxidant tests: DPPH scavenging, phosphomolybdenum method and oxygen radical absorbance (ORACFl and ORACPRG) assay. The results of the DPPH free radical and ORACFl assays showed that there is no significant difference between the EAc fraction and Oligopin(®), but the EAc fraction exhibited the highest antioxidant capacity as determined by the phosphomolybdenium method. In addition, the EtOH extract was determined to have the same antioxidant efficiency as the synthetic antioxidant BHT or commercial extract Oligopin(®) by phosphomolybdenum method. On the other hand, a positive correlation (r < 0.6) was found between different classes of polyphenols and the results of the phosphomolybdenum method, ORACFl as well as ORACPRG, except for the DPPH assay, for which a negative correlation was indicated (r < 0.62). Interestingly, it seems that the content in hydroxycinnamic acids played a big role in all assays with r < 0.9. According to the present study, EAc fraction and EtOH extract should be further studied for the potential use in the pharmaceutical and food industry.

Antioxidant capacity and amino acid analysis of Caralluma adscendens (Roxb.) Haw var. fimbriata (wall.) Grav. & Mayur. aerial parts.

Caralluma adscendens (Roxb.) Haw var. fimbriata (wall.) Grav. & Mayur. is a traditional food consumed as vegetable or pickle in arid regions of India and eaten during famines. In Indian traditional medicine, the plant is used to treat diabetes, inflammation and etc. The aim of this study was to evaluate the antioxidant properties (DPPH, TEAC, TAA, FRAP, OH˙ and NO˙ radical scavenging activities) of the different extracts from aerial parts. The levels of total phenolics and flavonoids of the extracts were also determined. The extracts were found to have different levels of antioxidant properties in the test models used. Methanol and water extracts had good total phenolic and flavonoid contents showed potent antioxidant and free radical scavenging activities. The antioxidant activity was correlated well with the amount of total phenolics present in the extracts. The extracts and its components may be used as an additive in food preparations and nutraceuticals.

Avaliação da atividade antioxidante e alelopática do extrato etanólico e frações das cascas do caule de Zanthoxylum rhoifolium Lam., Rutaceae / Assessment of antioxidant and allelopathic activities of ethanolic extract and solvent fractions from stem bark of Zanthoxylum rhoifolium Lam. (Rutaceae)

The purpose of this study was to test for antioxidantand allelopathic activities in stem bark of Zanthoxylum rhoifolium Lam., Rutaceae, with the eventual aim of discovering biologically active substances. The plant material was subjected to ethanolic extraction and this extract was partitioned, yielding hexane, chloroform, ethyl acetate and hydroalcoholic fractions. Antioxidant activity was estimated by the reduction of phosphomolybdenum complex, of DPPH. and of thiobarbituric acid-reactive substances (TBARS). To detect allelopathy, the samples were tested, at four concentrations, on the germination and development of the radicle and hypocotyl of L. sativa seeds. The samples showed significant antioxidant activity against the reduction of the phosphomolybdenum complex, as compared to rutin, and reduction of TBARS, ascompared to BHT, as well as allelopathic activity, since they stimulated growth and seed germination. The chloroform and ethyl acetate fractions showed the best antioxidant potentials, with 204.17% and 127.11% compared to rutin, in the reduction of phosphomolybdenum complex, as did the crude ethanolic extract and hexane fraction, with 64.2% and 60.9% compared to BHT, in the TBARS method. In the allelopathic assay, the chloroform fraction stood out as the only sample that stimulated the growth of both the radicle and hypocotyl at most concentrations, ranging from 41 to 144%, while the ethyl acetate fraction achieved the greatest stimulus in this bioassay, increasing the growth of the hypocotyl by 274%. This is the first study that demonstrates the antioxidant and allelopathic activities of the species Z. rhoifolium...

Este trabalho teve como objetivo o estudo das atividades antioxidante e alelopática das cascas do caule de Zanthoxylum rhoifolium Lam., Rutaceae, de modo a conduzir à descoberta de substâncias biologicamente ativas. O material vegetal foi submetido à extração etanólica e este extrato foi fracionado obtendo as frações (hexano, clorofórmio, acetato de etila e hidroalcoólica). Para a avaliação da atividade antioxidante, empregaram-se os métodos de redução do complexo fosfomolibdênio, de redução do radical DPPH e das substâncias reativas ao acido tiobarbitúrico (TBARS). Quanto à alelopatia, as amostras foram testadas em quatro concentrações sobre a germinação e o desenvolvimento de radícula e hipocótilo das sementes de Lactuca sativa. As amostras evidenciaram atividade antioxidante significativa frente ao método de redução do complexo fosfomolibdênio quando comparada à rutina, e do TBARS quando comparado ao BHT, assim como a atividade alelopática, uma vez que estimularam tanto a germinação como o crescimento das sementes. A fração clorofórmica e acetato de etila demonstraram melhor potencial antioxidante com 204,17% e 127,11% em relação à rutina no método de formação do complexo fosfomolibdênio, e o extrato bruto e a fração hexano com 64,2% e 60,9%, em relação ao BHT, no método TBARS. No ensaio alelopático, destaca-se a fração clorofórmica, pois foi a única amostra que estimulou o crescimento do hipocótilo e radícula na maioria das concentrações, variando de 41 a 144%, e a fração acetato de etila que apresentou a maior porcentagem de estímulo nesse bioensaio, demonstrando estímulo de 274% do crescimento do hipocótilo. Este é o primeiro trabalho que demonstra a atividade antioxidante e alelopática de Z. rhoifolium...

Loop flow analysis of dissolved reactive phosphorus in aqueous samples.

The current flow based method for the determination of dissolved reactive phosphorus (DRP) suffers interference from salinity (e.g. index refractive difference) and the incidentally formed bubbles, which can be a problem for optical detection. Here we reported a simple and robust loop flow analysis (LFA) method for accurate measurement of DRP in different aqueous samples. The chemistry is based on the classic phosphomolybdenum blue (PMB) reaction and the PMB formed in a novel cross-shaped flow cell was detected at 700 nm using a miniature spectrophotometer. The effects of reagents on the kinetic formation of PMB were evaluated. The detection limit was 32 nM with an optical pathlength of 1cm and the relative standard deviations for repetitive determinations of 1, 2 and 8 µM phosphate solutions were 1.8% (n=113, without any stoppage during repeating analysis for >7h), 1.0% (n=49) and 0.39% (n=9), respectively. The analysis time was 4 min sample(-1). The effects of salinity and interfering ions (silicate and arsenate) were evaluated and showed no interference under the proposed protocol for DRP analysis. Using the LFA method, different aqueous samples with a salinity range of 0-34 were analyzed and the results showed excellent agreement with the reference method (slope 0.9982±0.0063, R(2)=0.9987, n=34). Recoveries for spiked samples varied from 95.4% to 103.7%. The proposed method showed insignificant interference from salinity, silicate and arsenate, higher reproducibility, easier operation and was free of the bubble problem.

Effect of reverse photoperiod on in vitro regeneration and piperine production in Piper nigrum L.

In this study, a novel approach for in vitro regeneration of Piper nigrum L. has been applied in order to increase healthy biomass, phytochemicals and piperine production via reverse photoperiod (16hD/8hL). Leaf portions of the seed-derived plants were placed on an MS-medium fortified with different PGRs. Under 16hD/8hL, thidiazuron (TDZ; 4.0 mg L⁻¹) and BA (1.5 mg L⁻¹) was found to be the most effective (<90%) in callus induction. Two concentrations (1.5, 2.0 mg L⁻¹) of the IBA produced>80% shoots from callus cultures. Healthy shoots were transferred to rooting medium and higher percentage of rooting (<90%) was observed on IBA (1.5 mg L⁻¹). These in vitro tissues were subjected to amino acid analysis, spectrophotometry, and HPLC. ARG, SER, THR, and TYR were the most abundant components out of 17 amino acids. Higher amino acid production was observed under normal photoperiod (16hL/8hD) than under reverse photoperiod (16hD/8hL). The highest total phenolic content (TPC; 9.91 mg/g-DW) and flavonoid content (7.38 mg/g-DW) were observed in callus cultures incubated under 16hL/8hD than other tissues incubated under 16hD/8hL photoperiod. Higher DPPH and PoMo activities were observed in tissues incubated under 16hL/8hD photoperiod, while ABTS and Fe²âº chelating activities were found higher in tissues incubated under reverse photoperiod. Significant quantities of piperine content were observed in all tissues except callus cultures. These results suggest that reverse photoperiod is a promising approach for callus induction, phytochemicals and piperine production for commercial applications.

Atividade antioxidante e toxicidade preliminar do extrato e frações obtidas das folhas e cascas do caule de Dasyphyllum tomentosum (Spreng. ) Cabrera / Antioxidant activity and preliminary toxicity of the extracts and fractions obtained from the leaves and stem bark of Dasyphyllum tomentosum (Spreng. ) Cabrera

Dasyphyllum tomentosum (Spreng.) Cabrera, açucará ou espinho-de-agulha, pertence à família Asteraceae, a qual compreende muitas espécies com propriedades terapêuticas. O objetivo deste trabalho foi avaliar extratos e frações de folhas e de cascas do caule de D. tomentosum, com relação as atividade antioxidante, citotóxica e hemolítica em testes in vitro. Todas as amostras apresentaram atividade antioxidante pelo método de inibição de DPPH, com destaque para a fração acetato de etila obtida das folhas cuja atividade foi comparável à dos padrões ácido ascórbico e rutina. Com relação à redução do complexo fosfomolibdênio, observou-se que esta mesma fração foi semelhante somente a rutina enquanto a fração obtida das cascas do caule apresentou resultado superior. Não foi observada atividade citotóxica e hemolítica frente aos modelos utilizados com os extratos e frações. Os resultados obtidos demonstram o potencial antioxidante da espécie sem apresentar toxicidade.

Dasyphyllum tomentosum (Spreng.) Cabrera, which belongs to the Asteraceae family, is well known for having many species with therapeutic properties. The aim of this study was to evaluate the extracts and fractions from the leaves and stem bark of D. tomentosum with respect to the antioxidant, cytotoxic and hemolytic activity in in vitro tests. All samples showed antioxidant activity by the DPPH inhibition method, especially the ethyl acetate fraction obtained from the leaves, whose activity was comparable to that of standard ascorbic acid and rutin. Regarding the reduction of the phosphomolybdenum complex, we noted that this same fraction was only similar to rutin and the fraction obtained from the stem bark showed superior results. There was no cytotoxicity and hemolytic activity compared to the models used in the extracts and fractions. The results demonstrate the antioxidant potential of the species without showing toxicity.

Antioxidant capacity of extracts and isolated compounds from Stryphnodendron obovatum Benth / Capacidade antioxidante de extratos e compostos isolados de Stryphnodendron obovatum Benth

The extract from stem bark of Stryphnodendron obovatum Benth. was chromatographed on a Sephadex® LH-20 column, and yielded nine compounds: gallic acid (GA), p-hydroxybenzoic acid (PHB), gallocatechin (GC), epigallocatechin (EPG), 4'-O-methylgallocatechin (MGC), epigallocatechin-(4β→8)-epigallocatechin (EPEP), epigallocatechin-(4β→8)-gallocatechin (EPGC), robinetinidol-(4α→8)-gallocatechin (ROGC) and robinetinidol-(4β→8)-epigallocatechin (ROEP). Evaluation of the antioxidant capacity in vitro by the methods of DPPH free radical (IC50; μg/mL) and reduction of the phosphomolybdenum complex (RAC) gave the following results, respectively: crude extract 4.52 and 0.8242; ethyl-acetate fraction 4.04 and 0.9537; aqueous fraction 5.58 and 0.9275. The crude extract and ethyl-acetate fraction were shown to possess an antioxidant capacity comparable to that of vitamin C (4.93 and 1.0). The values obtained by the DPPH free-radical method for the isolated compounds were IC50 (μM): GA=8.89; PHB=10.12; GC=16.46; EPG=13.20; MGC=21.00; EPEP=6.89; EPGC=4.91; ROGC=7.78 and ROEP=6.20. Vitamin C and trolox showed 30.11 and 30.10, respectively. Dimers showed greater activity in scavenging free radicals, possibly related to the number of hydroxyls. However, compounds without a hydroxyl at position 5 of the A-ring (5-deoxy-proanthocyanidins) did not change the antioxidant activity of the DPPH free radical, as evaluated here for the first time. Among the monomers, there appeared to be a direct relationship in scavenging of free radicals because of the stereochemistry of the compounds. The presence of a methyl radical on the B-ring significantly reduced the scavenging of free radicals of gallocatechin. All compounds showed greater scavenging of radicals than vitamin C and trolox, and these two compounds showed no significant difference from each other.

O extrato das cascas de Stryphnodendron obovatum submetido à cromatografia em coluna, Sephadex® LH-20, forneceu nove substâncias: ácido gálico (GA), ácido p-hidróxibenzóico (PHB), galocatequina (GC), epigalocatequina (EPG), 4'-O-metilgalocatequina (MGC), epigalocatequina-(4β→8)-epigalocatequina (EPEP), epigalocatequina-(4β→8)-galocatequina (EPGC), robinetinidol-(4α→8)-galocatequina (ROGC) e robinetinidol-(4β→8)-epigalocatequina (ROEP). A capacidade antioxidante in vitro pelos métodos do radical livre DPPH (IC50; μg/mL) e do complexo fosfomolibdênio (CAR) apresentou os seguintes resultados, respectivamente: extrato bruto 4,52 e 0,8242; fração acetato de etila 4,04 e 0,9537 e fração aquosa 5,58 e 0,9275 demonstrando possuírem capacidade antioxidante quando comparados com vitamina C 4,93 e 1,0. Os valores obtidos pelo método do radical livre DPPH com as substâncias isoladas foram: IC50 (μM): GA=8,89; PHB=10,12; GC=16,46; EPG=13,20; MGC=21,00; EPEP=6,89; EPGC=4,91; ROGC=7,78 e ROEP=6,20. Vitamina C e trolox mostraram valores de 30,11 e 30,10, respectivamente. Os dímeros mostraram maior atividade no sequestro de radicais livres, possivelmente relacionada com o número de hidroxilas. No entanto, substâncias com ausência de hidroxila na posição 5 do anel A (5-desoxi-proantocianidinas) não alteraram o poder antioxidante frente ao radical livre DPPH, tendo sido avaliadas aqui pela primeira vez. Entre os monômeros, parece haver uma relação direta com a estereoquímica. A presença de um radical metila no anel B reduziu significativamente a atividade da galocatequina. Todas as substâncias isoladas mostraram maior atividade do que a vitamina C e trolox, e estes não mostraram diferença significativa entre si.

Atividade antioxidante das folhas de espinheira-santa - Maytenus ilicifolia Mart. ex Reiss., secas em diferentes temperaturas / Antioxidant activity of "espinheira-santa" - Maytenus ilicifolia Mart. ex Reiss., leaves dried in different temperatures

Maytenus ilicifolia Mart. ex Reiss, a espinheira-santa verdadeira, é largamente utilizada para tratamento de gastrites e úlceras estomacais. O seu valor terapêutico é atribuído principalmente aos polifenóis (flavonóides e taninos) e triterpenos. Os polifenóis são bastante estudados e estão relacionados à atividade antioxidante exercida pela planta. Existem vários métodos para avaliar a atividade antioxidante, a qual pode ser medida a capacidade antioxidante total utilizando o método de formação do complexo fosfomolibdênio e a atividade antioxidante em relação à redução de um radical, utilizando-se o DPPH (2,2-difenil-1-picrilhidrazila). A atividade antioxidante das folhas de espinheira-santa seca em diferentes temperaturas foi avaliada, visando verificar a possível influência das temperaturas de secagens e seu poder antioxidante. Foram utilizadas cinco temperaturas (40, 50, 60, 70 e 80 ºC) e uma temperatura de secagem de rotina, de um produtor/beneficiador de plantas medicinais. As menores temperaturas apresentaram as maiores atividades antioxidantes.

Maytenus ilicifolia Mart. ex Reiss, the true "espinheira-santa" is widely used for treating gastritis and stomach ulcers. Its therapeutic values are due mainly polyphenols (flavonoids and tannins) and triterpens. Polyphenols are largely studied and they are related to the antioxidant activity of the plants. There are several methods for evaluating the antioxidant activity, which can measured the total antioxidant capacity through the formation of a phosphomolybdenum complex and the antioxidant activity related to the reduction of one radical, using the DPPH (2,2-diphenyl-1-picrylhydrazyl). The antioxidant activity of "espinheira-santa" dried leaves in different temperatures was measured in order to evaluated the possible influence of drying temperatures under its antioxidant power. Five temperatures used were (40, 50, 60, 70 and 80 ºC) and a drying routine of medicinal plants as well. Lower temperatures showed the highest antioxidant activities.

Determination of Phosphorus in Human Hair by Spectrophotometry of Phosphomolybdenum Blue / 昆明医科大学学报

This paper reported a method of determination of phosphorus in human hair by Spectrophotometry of phosphomolybdenum Blue.Samples were decomposed by means of dry ashing.Vitamin C was used as a reducing agent.The conditions of ashing and colouration of phosphomolybdehum Blue,the measurement wavelength and the confidence of this meth od were also studied.